Its roots were in Hoxhaite revisionism; however, Gorbachev and parties including one in Iran moved away from Stalin and "back to Lenin." That maneuver of the late 1980s and early 1990s well-suited Khruschev-spawn like Gorbachev and the Communist Voice Organization. It was their hope to make the international communist movement forget about the past and unite without one under the banner of "Marxism-Leninism"--a motley collection of Gorbachevites, ex-Trotskyists and ex-Hoxhaites.
A March, 1999 publication rediscovers the Progressive Labor Party line on the Cultural Revolution without naming it such. The same publication correctly condemning post-modernism also supports the nihilism of the Red Guard ultraleftists whose ideology has yet to accomplish anything in the world except to serve as a source of criticism of Marxism similar to post-modernism.
See http://www.flash.net/~comvoice/
Further Info: "MLP Statement," MT6
($6).